The present invention relates to a virtual computer system and a method of controlling the same. In particular, the present invention relates to a control technique that moves an operating system (virtual computer) operating on a virtual computer system on a physical computer to a virtual computer system on another physical computer.
As the number of servers increases, the complexity related to the operation of a computer system increases and the operational cost becomes an issue. Server integration, which integrates plural servers into one, has recently been focused on as a technology for reducing operational cost. Virtual computers, in which one computer is logically divided by an arbitrary ratio, are known as a technology for achieving server integration. A physical computer is divided into plural logical partitions (hereinafter, referred to as LPAR) by firmware such as a hypervisor (or middleware), and computer resources (a CPU, a main storage device, and an I/O device) are assigned to each of the LPARs, thereby realizing virtual computers which each operate a corresponding operating system on a corresponding LPAR. As a result, a CPU is time-divided, which makes flexible server integration possible. An example of such a virtual computer is disclosed in JP-A-2005-309553.
Further, in order to allow for an increase in a usage rate of physical computer resources, maintenance of physical computer hardware, etc., an operating system (virtual computer), which is operating, can be moved between plural virtual computer systems on a physical computer, which improves the flexibility of a system operation. An example of such a virtual-computer moving method is disclosed in JP-A-1998-283210.